1. Technological Field
The present invention relates generally to fluid system components. More particularly, embodiments of the present invention relate to coupling elements for fluid system components, in which the coupling elements facilitate quick and efficient coupling/decoupling of the fluid system components for the introduction of a fluid system cleaning device. Further, embodiments of the present invention relate to fluid system components which substantially prevent inadvertent, unintentional and/or undesired removal of a coupling element until the fluid system line pressure, or relative pressure differential, is reduced to a safe level.
2. Related Technology
Pipes used in fluid systems, such as those found at chemical plants, oil refineries, power generation plants, mines, paint manufacturing, lubricant blending, steel mills, pulp and paper plants, water filtration, sewage treatment plants, food processing, and the like, often carry contaminants that become deposited on the inside of the pipes. These contaminants can be extremely hard, such as coke, calcium, silica, sulfur, iron sulfides and types of ceramic. Build up of these contaminants can cause a variety of problems from reduced production to rupture of the pipe.
Various methods have been used to clean the inside of pipes. For example, some exemplary methods include steel shot blasting, high pressure water blasting and chemical cleaning. Notably, in each of these methods, at least some of the deposited contaminants are removed from the walls of the pipe. While effective for removal of such contaminants, however, such methods may also not effect complete removal (or as complete removal as is desired) and/or can increase pipe erosion and sagging, present fire hazards and/or environmental concerns, require long shut down periods, thereby also resulting in high cost and decreased production run lengths.
Accordingly, other methods for cleaning the inside of pipes have been developed. Once such method include the use of cleaning devices generally known as pigs. Pigs are available in a wide variety, and can include, for example, mandrel pigs, foam pigs, solid cast pigs, spherical pigs, geometry pigs, and gel pigs. Any such pig may be shaped to substantially conform to the interior of the pipes and can be propelled through the pipes to clean the interior of the pipes. In some cases, the pig can have appendages, such as brushes, disposed circumferentially around and extending radially outward from the body of the pig. As such, a pig is forced through the pipe—by using hydraulic pressure for example—and the appendages remove the contaminants from the inside of the pipe. Pigs may also be used for other purposes other than cleaning. For instance, pigs may be used to separate dissimilar products, dewater a pipe, provide information on the condition inside the pipe (including the extent, nature and location of any problems), and to dry the inside of a pipe.
For whatever purpose the pig is used, the pig is typically introduced into a fluid system pipe through a flange. Removing and replacing a flange can require significant time. A typical flange, for instance, will be secured to the end of a pipe with several studs/bolts and nuts. For example, to disengage an ANSI 300# flanges, an operator must undo twelve studs with two nuts per stud. Once the flange has been disengaged and the pig has been inserted into the pipe, the operator must then couple the flange to the end of the pipe by tightening the twenty-four nuts back onto the twelve studs. Due to the delays in disengaging such flanges, such pigging systems can therefore also result in shut down times that are longer than desired, and increase the overall costs while reducing production run lengths.
Moreover, introducing a pig into a pipe through a typical flange may also pose significant safety and/or environmental risks. For instance, typical flanges are configured so that an operator can uncouple the bolts of the flanges even in the presence of line pressure.
In the event the line wherein the flange is located is charged with hazardous materials (e.g., chemicals, sewage, fuels, or gases such as chlorine and methane) the operator performing the uncoupling operation could be seriously injured or killed when such materials escape from the line, and possibly at a very high velocity. Moreover, such hazardous materials may include pollutants, and significant time and cost is often involved in the cleanup of such materials.
A related feature of such typical flanges concerns the pressure exerted by the material in the line wherein the flange is located. In particular, such pressure may cause the flange to rapidly separate from the pipe in an uncontrolled and dangerous manner, thereby injuring the operator and/or damaging nearby equipment. The forces resulting from such pressure can often be significant, even where the line pressure is relatively low. Thus, in a six inch diameter (nominal) pipe for example, even a relatively low pressure of ten psi) would exert a force of about one thousand pounds on a flange attached to the end of the pipe.
Not only are such pressures potentially dangerous, but operators may not have any way to verify, in advance of performing the uncoupling operation, whether or not the line is pressurized. Further, even if a mechanism exists for informing the operator whether line pressure is present, it may require a high degree of vigilance on the part of the operator and/or the operator may, through inattentiveness, negligence, or for other reasons, nevertheless attempt to uncouple the flange from the pipe.
In view of the foregoing, it is therefore desirable to have a fluid system component that facilitates the secure engagement, and ready disengagement, of mating halves of the fluid system component. Such a component can, for example, facilitate quick and convenient insertion or removal of a pig from a fluid system pipe, while at the same time optionally preventing intentional or accidental disengagement of the mating halves when a predetermined pressure is present in the line.